Currently, pneumatically operated, angle die grinders support a very large variety of tools that include disc sanders, drum sanders, cutoff wheels, bun tools of all kinds, buffers, wire wheels and stirrers. Each of these tools comes in a large number of sizes and shapes, each specific to their applications. Typically, pneumatically operated, angle die grinders are used in automotive body shops as well as any type of work shop where surface finishing is done.
Generally speaking, these angle die grinders provide rotary motion of abrasive surface materials such as sandpaper discs, belts, and drums. Commonly, angle grinders consist of a hand-held motor portion, driven electrically or pneumatically, and a rotating output shaft portion that holds a wheel upon which is disposed a disc of surface treatment material such as sand paper. The axis of rotation of the rotating output shaft with the wheel secured to one end is disposed at an angle, commonly about 90 degrees, to the axis of rotation of the motor. In some angle grinders, the angle is adjustable over a range, so as to provide ease of access to surfaces being ground, sanded or otherwise treated, as in polishing, buffing and like surface treatments.
In the case of grinding where the abrasive material is commonly a rotating disc of sandpaper or equivalent abrasive material, the rotary motion that is delivered to the disc by means of a wheel to which the disc is attached by various means such as, commonly, a central screw or adhesive.